I did it! I got my Tandy 1000SX on the internet!
This is an XT-class machine with 640K RAM and the CPU replaced with an NEC V20. The only thing not era-specific is the modern XT-IDE controller with 2 gig CF card in it. I found an old Intel Etherexpress 8/16 on eBay for a lot cheaper than the 3com 8-bit NICs with twisted pair, and it's still easy to find the dos drivers. I started with mTCP and the packet driver from e16disk. After I got that going, I grabbed the later doslynx, which was just as simple to get working. Only thing that sucks is the https support is missing, and, with the push to https everywhere, this really breaks web browsing from doslynx.